Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 0%, so the description must compensate for four undocumented parameters, and it barely does. 'Control-point' loosely points at controlPoints, but unit, layer, and degree are never explained and the controlPoints format (min 2 points, x/y required) is left entirely to the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.